You are doing what you can! The vitamins will take a couple days to make a difference. If she is not in pain, I would give her a few days and see if there is improvement.
Good luck and keep us posted!
It may be a simple fix.
I have had luck with supplementing vitamins. Ducks need more niacin than chicken and niacin defieciency that can cause wry neck.
You can sprinkle brewers yeast on the food or if you don't have any one hand, a few drops of PolyViSol twice a day for 3 or 4 days usually...